package objectTest;

class Plane {
    double length;
    double width;
    double height;
    double weight;
    public void fly(){
        System.out.println("飞");
    }
    //直升机
    public class Copter extends Plane {
    }

    //喷气飞机
    public class JetPlane extends Plane {
    }

    //战斗机

}
